Email Validation Using jQuery

email-validation.js

jQuery(document).ready(function(e) {
    jQuery('.submit-button-class').click(function() {
        var valEmail = jQuery('.email-field-class').val();
        if (jQuery.trim(valEmail).length == 0) {
            alert('Please enter valid email address');
            e.preventDefault();
        }
        if (validateEmail(valEmail)) {  
        }
        else {
            alert('Invalid Email Address');
            e.preventDefault();
        }
    });
});
function validateEmail(valEmail) {
    var filter = /^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
    if (filter.test(valEmail)) {
        return true;
    }
    else {
        return false;
    }
}